Research Progress on the Hot Corrosion Behavior and Improvement Method of Single Crystal Superalloys

Author of the article:LI Jiayu1 , FAN Jiangkun1,2, SONG Yuelin1 , YANG Hongci1 , YUAN Ruihao1,2, KOU Hongchao1,2, LI Jinshan12

Author's Workplace：1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China; 2. National and Local Joint Engineering Research Center for Precision Thermoforming Technology of Advanced Metal Materials, Xi'an 710072, China

Key Words：single crystal superalloy; hot corrosion; service performance; improvement methods

Abstract：Single crystal superalloys are an important material for manufacturing aero-engines and gas turbine hot-end turbine blades. However, the presence of corrosive gas in the working environment of single crystal blades seriously affects their service life. This paper reviews the development of nickel-based superalloys in recent years, focusing on the hot corrosion behavior of single-crystal superalloys. According to the typical applications and real service conditions of single crystal superalloys, the molten salt corrosion mechanism model, stress corrosion and hot corrosion fatigue, and the orientation of anisotropic hot corrosion behavior are introduced. The methods for improving the hot corrosion resistance of single crystal superalloys are introduced from four aspects: composition regulation, the addition of rare earth elements, anti-corrosion coating, and surface modification technology. Finally, based on the analysis of the existing research results, the challenges in the research of hot corrosion of single-crystal superalloys are summarized, and possible research directions in the field of hot corrosion behavior of single-crystal superalloys in the future are also proposed.